Means for directing electric waves for use in wireless telegraphy.



PATENTED NOV. 24, 1908.

P. BRAUN. MEANS FOR DIREGTING ELECTRIC WAVES FOR USE IN WIRELESS TELEGRAPHY.

' APPLICATION FILED FEB. 19, 1902.

H0 MODEL.

fiwerrfd 7" normal tothe plane of the drawings.

.rods A A A A A UNITED STATES Patented November 24, 1903.

ATENT Fries.-

FERDINAND BRAUN, ORSTRASSBURG, GERMANY.

' MEANS FOR DIRECTING ELECTRIC WAVES FOR USE IN WIRELESS TELEGRAPHY;

SPECIFICATION forming part of Letters Patent No. 744,897, dated November 24, 1909.

' Application filed February 19, 1902. Bunnie-84,729. No model.)

To aZZ ;wh'0m it may concern:

Be it known that I, FERDINAND BRAUN, a subject of the Emperor of Germany, residing at Strassburg, Germany, (whose post-oflice address is No. 1 Universitatstrasse, Strass burg,Alsace, German Empire) have invented new and useful Improvements in Means for Directing Electric Waves to be Used in Wireless Telegraphy, of which .the following is a specification.

The present invention relates to reflectors adapted for use in connection with wireless telegraphyfor the purpose of imparting to the electric waves a certain direction of propagation. I

It consists principally in a metallic grating ofparabolic or similar form constructed or arranged in anovel manner, hereinafter more fully described.

The invention is shown in ing drawings, of which- Figure 1 is a diagrammatic View illustratmg the theoretical physical principle. Fig. 2 is a section of the new reflector. Fig. 3 is a perspective view, while Fig. 4 represents an improvement of the reflector by means of deflectors.

Itis well known in optics that series of luminous lines located in one plane and parallel to each other at equal distances apart and having the same phase and amplitude of oscillation will produce what is called in opticalscience a wave front which is a plane. These lines are indicated in Fig. 1 by points A A A A which represent sections of the luminous lines making up the wave front The same efiect can also be obtained by the arrangegnent of a parabolic mirror. If,-for instance, in Fig. 2 F is the luminous point and. A A A A A? are parts of a parabolical mirror-of cylindrical shape, W W will indicate the wave front which is a plane. This method maybe employed for wireless telegraphy in the. following manner: A series of parallel are arranged at equal distances from each other, so as to produce a cylindrical parabolical mirror in the form of a grating. Each rod is connected by a straight wire to a small ball F, set in the focus-line of the mirror. As shown in Fig. 3, two sets of the accompany- (Not shown.) Now it will be rods are provided for, and .between the two A balls F F set in the focus-line a spark is generated from time to time by a Ruhmkorif apparatus or an electrical static machine-.- evident that as all rods are excited from the same center and as the phase difference of the oscillations 9f thesingle rods is determined by the length of the corresponding wires the set of rods act in such manner as to generate a wave front which must be in a plane. The wave motion therefore will be essentially rectilineal. It is obvious that by these means the greatest amount of the radiating energy will be guided in one direction. The phenomenon is physically analogous to the ordinary parabolic mirror and to IIertzs mirror for electric waves. Its peculiarity,however, is that every rod fulfils its own oscillation, provided it is tuned by ordinary means, as capacity and self-induction, to the same periodicity.-

The advantage of the new system over the ordinary metallic continuous parabolic mirror is that much more energy is set inaction, as the energy depends on the capacity of the sin gle rods,which may be increased by increasing the capacity of the'rods and adding, for instance, condensers to the same. A further advantage maybe secured by suitable additional rods ab 0, Fig. 4, or similar bodies-as, for instance, human bodies. These bodies act to prevent lateral deflection.

What I'claim, and desire to secure by Letters Patent of the United States, isle- 1. In mirrors for wireless telegr phy the combination of sets of rods tunedto he same frequency arranged parallel to each other in a parabolic cylindrical surface, spark-balls for electric disruptive discharge, and wires connecting the balls and the said rods, substantially as and for the purpose described.- 2. In mirrors for wireless telegraphy, the combination of sets of rods tuned to the same frequency arranged parallel to each other in a parabolic cylindrical surface, and sparkballs for electric disruptive discharge, said balls being arranged in the center line of the parabolic cylindrical surface, as set forth.

3. In mirrors for wireless telegraphy, the combination of sets of rods tuned to the same frequency arranged parallel to each other in a parabolic cylindrical surface, spark-balls In testimonywhereof I have hereunto set for electric disruptive discharge, said balls my hand in presence of two'subscribing witbeing arranged in the center line of tile paranesses. bolic cylindrical s1'1rface,'wires connecting I FERDINAND BRAUN.

5 the balls and said rods, and deflecting rods Witnesses:

arranged parallel to the said center line, snb- MATHIAS CANTO'R, stantially as and for the purpose described. MARIA SOHORN. 

